Production of cyanogen compounds.



CARL BOIEFCH, OF LUDWlG-SHAFEN-ON-THE-Rlilbll l, GlERhIlANY, ASSlG-NOR TO BADlSUliE Allllldll (SI: SODA FARR! K, ()F LUDWlGb RHINE, GERMANY, A

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Specification of Letters Patent.

H A lBEN-ON-THE- CORPQRATIDN OF GERMANY.

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Ira-tented May 22, 1906.

Application filed April 1 1905. Serial No. 253.318.

* To (all) whom it TIT/(23y concern:

lite it known that I, CARL Boson, a subject of the King of Prussia, German Emperor, residing at Ludwigshafen-on-the-Rhine,in the Kingdom of Bavaria, German Empire, have invented new and useful Improvements in the Production. of Cyanogen Compounds, of which the following is a specification.

The preparation of technically-pure cyano gen com o'uuds from raw melts as hitherto practice leaves much to be desired as re gards the yields-obtained, and the alkali em ployed in the preparation is usually obtained in a form which requires special treatment before it can be reused.

The object oi my invention is to overcome these objections and obtain excellent yields of technically-pure cyanogen compounds. According to my invention, Water and an ammonium salt are added to the raw melt and the mixture is distilled, ammonium cyanid passing over, the yield being almost quantitative. Any suitable. ammonium salt me be used; but I prefer to use one which will? convert the base of the raw melt into a form in which it can be directly employed a air. in the production of fresh raw melts. The employment of ammonium; carbonate of fers a special advantage, because barbonioacid gas, even in. a dilute forin, 'can be easily converted into ammonium carbonate, and

thus be used indirectly for setting free the hydrocyanic acid from the raw melt, and this is an improvement upon driving oil. the hyd rocyanic acid from the raw melt by heating with mineral acid. v It is preferable that the distillate containing ammonium cyanid be Worked up without de lay, and this can be effected by theaddition either of acid or alkali.

In the process according to my invention sulfur compounds contained in the raw melt form ammonium sulfid, which distils over with the ammonium cyanid Without forming sulfocyanid compounds, and this ammonium sul fid, and also any free sulfur, can be easily removed by bringing the gascsinto contact with a suitable salt of the heavy metals, either in the solid form or in solution or as a paste.

The process according to my invention is preferably carried out in some with a con- (lensing column above the distilling vessel,

because then a concentrated. distillate is obtained, the poisonous gases do not escape from the apparatus, and the distillation can be carried out at a lower temperature, thereby decreasing the liability to saponification oi the hydrocyanic acid into formic acid.

The process according to my invention is especially useful. when the raw cyanlds of the alkaline-earth metals and ammonium carbon etc are used, as then the alkaline-earth carbonates are obtained as by-products and can be directly used over again in a subsequent operation, while ammonium carbonate does not pass over with. the distillate when distilling in the presence of water as it does in dry distillation.

The-following examples will serve to further illustrate the nature of my invention, which, however, is not confined to these examples. The arts are by weight.

Examplei issolve in water one hundred and twenty-five (125) parts of p0tassiumcyanid melt, (containing about seventy-six. (76) oer cent. of potassium cyanid and twentyour (24) per cent. of potassium cyauate. Add to the solution. ninety() parts of am- .monium chlorid and then distil, collecting the distillate in an equivalent quantity of causticsoda solution, which is maintained at a tem perature of about forty (40) degrees centigrade. When the gases being distilled over contain no more hydrocyanic acid; the distillation is stopped and the sodium-cyanid solution obtained is evaporated referably in vacuo) and the ammonia whic 1 is liberated can becollected.

Example 2: Stir with eight (8) parts of Water one (1) part of-raw barium cyanid, for instance, such as is obtained by Margucritte and Sourdevals process. Pass carbonic-acid gas into the mixture until the barium hydrate contained therein is neutralized and then, add a solution of ammonium carbonate in quantity equivalent to the amount of cyanogen. obtained. Mter stirring for a short time distil in vacuo and. continue heating until all the ammonium cyanid has distilled over. Collect the distillate in a solution of caustic soda which contains so much of the alkali that at the end of the operations solu tion oi practically pure sodium cysnid is obtained. This solution can be worked 1 p as described in the foregoing Example 1.

4 If desired, the ammonium cyanid which distils over can be passed into acid, and the hydrocyenic acid which is set freecan be collected and worked up in any suitable manner.

N ow what I claim is 1; The process for the production hf technically-pure cyanogen compounds which consists in distilling crude cyanid melts with an ammonium salt in the presence of Water.

2. The process for the production of tGUhr nically-pure cyanogen compounds which consists in distilling in a vacuum crude cyanid melts with an a'nmionium salt in thepresence of water. r

v 3. The process for the production of technically-pure alkali cyanid which consists in distilling in a vacuum crude cyanid melts witnesses.

with an ammonium salt in the presence of Water, and treating the ammonium cyanid' which distils over with caustic alkali. 5

a 4. The process for the production of tech- 2o nically-pure sodium cyanid which consists in heating in a vacuum crude pyanid igelts with an ammonium salt in the presence of water and treating the ammonium cyanid which distils over with caustic soda. z 5 In testimony whereof I have hereunto set my hand in the presence of two subscribing CARL BESCH. Witnesses:

J. ALEo. LLOYD, Jos. H. LEUTE. 

